Viral foodborn illness are caused by Food born viruses which can contaminate food and beverages. Foodborn viruses are originate from human intestine.

1. Viral foodborn illness
Submitted by,
P. SANGEETHA..
19308021.
M.sc. Microbiology.

2. Foodborn virus
Viral foodborn illness are caused
by Food born viruses which can
contaminate food and beverages.
Foodborn viruses are originate
from human intestine.
Eg: Norovirus, hepatitis A virus.
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3. Major Foodborn virus
▧ Norwalk virus
▧ Hepatitis A virus
▧ Rotavirus
▧ Adenovirus
▧ Parvovirus
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4. Norovirus
▧ “ Norovirus” was designated as the official genus name for the group
of viruses previously described as “Norwalk-like viruses’ (NLV).
▧ First reported in 1972 by kapikian and colleagues. Small round
structured virus – 27nm.
▧ Family- calciviridae (means cuplike structure).
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▧ 5 genera –Vesivirus, Lagovirus,
Norovirus, Sapovirus, Unclassified
genera.
▧ Norovirus causes gasteroenteritis- an
inflammation of the gastrointenstinal
tract.

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Characteristics:
▧ The Caliciviridae family of small, nonenveloped
▧ The human norovirus genome is composed of a linear, positive-
sense RNA that is ∼7.6 kb in length
▧ Highly contagious
▧ Multiple mode of transmission
▧ Stable in the environment
▧ Resistant to routine disinfection methods
▧ Carriers may not be symptomatic
▧ these viruses seem to be evolving rapidly,
and there are many strains.

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Epidemiology :
▧ Norovirus causing foodnorn illness, about 685 million cases annually.
▧ The first documented epidemiologic linkage between human NoVs and
shellfish-associated gastroenteritis occurred in the mid-1970s, and many
more outbreaks have been reported since then for example,three large
outbreaks associated with improper discharge of untreated human waste
material occurred in Louisiana in the 1990s alone.
▧ Between 2003 and 2004, three distinct human NoV outbreaks in Australia
were associated with the consumption of imported oyster meat. In 2010, 334
NoV cases associated with shellfish consumption were reported in five
European countries.

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Symptoms:
▧ Vomiting, diarrhoea and abdominal pain.
▧ Inflammation of the stomach.
▧ Duration of symptoms varies from 12-72 hours depanding on number of
virus particle consumed but, after the initial uncontrollable onset, the
symptoms may be relatively mild.

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Mode of Transmission:
▧ Fecal oral transmission.
▧ Person to person
▧ Ingestion of contaminated foods or beverages.
▧ Contamination with small numbers of norovirus particle can be
enough to cause disease, with only approximately 100 particles
needed.
Food source:
▧ Shellfish, (oysters)
▧ hand-sliced deli meats and cheeses;
▧ vegetable, and fruit salads; and various
desserts.
▧ Ready to eat (RTE) foods, such as
sandwiches, salads and baked products

9. Prevention
▧ Wash your hands often
▧ Wash fruits and vegatables.
▧ Cool shelfish thoroughly.
▧ After voming or having diarrhea immediately clean and
disinfect surface and hand.
▧ When you are sick, don’t prepare food or care for others.
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Treatment:
▧ Oral fluid and electrolyte replacement therapy is usually adequate for
replenishing fluid loss.
▧ The symptoms of the disease can also be reduced by the oral administration
of bismuth subsalicylate

11. Hepatitis A
▧ Hepatitis A is a viral liver disease that can cause
mild to severe illness.
▧ The hepatitis A virus (HAV) is transmitted through
ingestion of contaminated food and water or
through direct contact with an infectious person.
▧ First identified in 1973.
▧ Family: picornaviridae
▧ Genus: Hapatovirus
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▧ The virus is a naked, round particle with a diameter of 27 to 32 nm.
▧ Its genome is a linear, single-stranded, 7.5-kb positive-sense RNA
molecule that is enclosed in an icosahedral capsid that consists of three
major proteins designated VP1, VP2, and VP3.

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Characteristics:
▧ Acid resistance – able to retain infectivity below pH 3.
▧ HAV is a stable virus that can survive for long periods in the environment, in
seawater, freshwater ,groundwater, and soil.
▧ Temperature resistance- HAV remains infectious after refrigeration and
freezing: consequently, frozen fruits can and have been implicated in
hepatitis A outbreaks.
▧ Retains infectivity after heating to 60°C for 30min.
Symptoms:
▧ Symptoms of hepatitis A range from mild to severe, and can include fever,
▧ malaise, loss of appetite,
▧ diarrhea,
▧ nausea,
▧ abdominal discomfort,
▧ dark-coloured urine and jaundice.

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Epidemiolgy
▧ Current estimates of food-related illness in the United States suggest that
hepatitis A is the fourth leading cause of viral foodborne illness
▧ The majority of hepatitis A outbreaks in England and Wales are small and
occur in families. The last recorded foodborne outbreak was in 1992 and was
associated with shellfish ingestion .
▧ From 1992 to 1999, the Public Health Laboratory Service (now the Health
Protection Agency) received 19,747 laboratory-confirmed reports of
hepatitis A.
▧ The source of most infections was unknown, and only 155 cases were
recorded as being foodborne.

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Transmission:
▧ The hepatitis A virus is transmitted
primarily by the fecal-oral route; that is
when an uninfected person ingests food
or water that has been contaminated
with the faeces of an infected person.
▧ sewage-contaminated or inadequately
treated water.
▧ Contaminated food.

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Pathogenesis
▧ HAV is not neutralized by gastric acid
and is thought to be transported
across the intestinal epithelium to be
taken up by hepatocytes The main
target organ is the liver.
▧ Viral replication occurs in the
cytoplasm of the infected hepatocytes
▧ The incubation period of hepatitis A is
15–50 d with a mean of about 30 d.
▧ Viral is shed in large quantity into the stool approximately 10 days
before symptoms of jaundice appear or antibody can be detected.

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Source of virus:
▧ Sewage discharge and leaks
▧ Contaminated irrigation water- fruits, salads,and vegetables.
▧ Food handlers- mainly cold foods or foods that do not receive
further cooking after handling, eg: salads, sandwiches, fruits,
cakes and cream.
Diagnosis:
▧ Specific diagnosis is made by the detection of
HAV-specific Immunoglobulin G (IgM) antibodies
in the blood.
▧ Additional tests include reverse transcriptase polymerase chain reaction
(RT-PCR) to detect the hepatitis A virus RNA and may require specialized
laboratory facilities.

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Prevention:
▧ Adequate supplies of safe drinking water.
▧ Proper vaccination
▧ proper disposal of sewage within communities; and
▧ personal hygiene practices such as regular hand-washing before meals and
after going to the bathroom.
Treatment:
▧ Hospitalization is unnecessary in the absence of acute liver failure.
▧ Administration of Igs at doses as low as 0.01 to 0.04 ml/kg of body weight
were used for HAV postexposure prophylaxis.
▧ These can be effective in controlling both the incidence and severity of disease
as long as they are administered within 2 weeks of exposure.
▧ The prophylactic administration of Ig is recommended for patrons food
handlers.

18. Rota virus
▧ Family- Reoviridae
▧ Genus- Rotavirus
▧ five species (type A to E )
▧ Type A causes gastroenteritis and dehydration in infants, milder
disease in older children, life-threatening diahhrea.
▧ Type B most often associated with large epidemics in human,
children and adults in china and causes severe gastroenterities.
Role of foodborn transmission:
▧ Rotavirus foodborn outbreaks documented but rare.
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19. Adenovirus
▧ Family- Adenoviridae
▧ Cause acute infantile gastroenteritis, second in prevalence to that
caused by rotavirus.
Role of food born transmission:
▧ Credible but not documented.
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20. Reference:
▧ Food microbiology : fundamentals and frontiers, 4th edition,
Michael P.Doyle and Robert L.buchanan.
▧ Modern food microbiology, seventh edition, James M.Jay, Martin
J.Loessner, David A.Golden.
▧ Robilotti, Elizabeth, Stan Deresinski, and Benjamin A. Pinsky.
"Norovirus." Clinical microbiology reviews 28.1 (2015): 134-164.
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21. Thank you!
“ The foodyou eat can be either the
Safest and Most powerful
form of the Medicine, or the
slowest form of Poison.”
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